1. Field of the Invention
The present invention relates in general to watercraft, and in particular to an improved speed sensor for a personal watercraft.
2. Description of Related Art
Personal watercraft have become popular in recent years. This type of watercraft is sporting in nature; it turns swiftly, is easily maneuverable, and accelerates quickly. Personal watercraft today commonly carry one rider and one or two passengers.
A relatively light weight, small hull of the personal watercraft defines an engine compartment below a rider's area. An internal combustion engine frequently lies within the engine compartment in front of a tunnel formed on the underside of the watercraft hull. The internal combustion engine commonly powers a jet propulsion device located within the tunnel. An impeller shaft commonly extends between the engine and the propulsion device for this purpose. Such small watercraft today are capable of traveling at high rates of speed.
Personal watercraft often include some types of instrumentation to optimize the performance of the watercraft, as well as to monitor various operational characteristics of the watercraft's performance. In this regard, the personal watercraft usually includes a speedometer not only to allow the operator to monitor the speed of the watercraft, but also to control trim and other factors in order to maintain optimum performance.
Most speed indicators require a component of the indicator to be mounted on the underside of the hull. In this position, the component lies within the water and generates a signal indicative of the watercraft's speed. The hull of a personal watercraft, however, does not have large areas on which to mount conventional speed sensors. Most of the practical surface on the underside of the hull is occupied by the jet pump unit that is positioned within the tunnel.
As a result of the limited space on the underside of the hull, speed indicators are usually mounted proximate to the stern of the watercraft, near a nozzle section of the jet pump unit (see FIG. 23 of the appended drawings). This location of the speed indicator, however, often results in an overly complicate layout of the steering nozzle and of the associated lever and cable in order to work around the speed indicator. In addition, the speed indicator extends below the planing surface of the lower hull at this location and consequently is susceptible to damage. The speed indicator is also visible from the rear of the watercraft when mounted at this location, which lessens the appearance of watercraft.